Safety cutoff valve



T. J. SULLIVAN SAFETY CUTOFF VALVE Filed April 23. 1952 Temperqfure- Bevan/re May 5, 1953 Patented May 5, 1953 STATES PATENT OFFICE SAFETY (JUTOFF"VALVE' Application April 23, 1952,- Serial .No. 283391;

6 Claims.

This invention relates to saiety'cutwif, valves,

for use in pressure gas lines such asthefuelsupply line to gas-fired heaters and boilers ofdomestic or industrial types, and more particularly.

to a valve which operates automatically to shut oil the supply of gas to a burner upon theoccurrence of one oi a number of abnormalcondi-- tions and which must be manually reset to restore operation of the burner.

An object of the invention is to provide a cutoff valve which closes automatically under certain abnormal conditions and which may be manually reset to open only after removal of all labno ll conditions which would result in an imate reclosure oft-the valve. More particular objects are to provide a manually reset cut-ofi valve which closes automatically in the event of abnormally high or low pressure on the controlled line, or" abnormal temperatures as in the case of fire, of a failure of the electrical control circuits and/or an earthquake or other severe shock which might damage the piping of the supply system; the construction being such that the valve can be reset in normal manner only after correction of the abnormal condition. Other objects are to provide a manually reset cut-off valve of the character stated which can be partially orcompletely opened if that is necessary to remove the abnormal condition which caused the closure of the safety valve, for example to re-light a pilot flame, or to restore service without theprotection of the cut-off valve as an emergency measure.

lhese and other objectsand the advantages of the invention will be apparent from the "following specification when taken with the accompanying drawing, in which:

Fig. l is a fragmentary side elevation of a gasfired furnace having a cut-off valve embodying the invention in the gas supply line in advance matically controlled valve and associated equipmentpt desired or conventional typewhich is indicatedlbythe block 3 and legend Controls.

The gas-line 4. beyond the automatic controls 3- entersthe .furnace 5' to feed the burners, not

shown.

The valve, casing; I divided into an inlet and an outletchamber by a partition in which a valve seatbushingfi is set, and the cooperating valve element I is of conventional inverted cup type with raduatedslots in its sleeveseotion. The valve element 'a' is carried by a; hollow valve stem 8 having an inletport 9 which opens into the inlet chamber of thevalve-casing; the valvestem extending upwardly through a diaphragm cham-- ber, It to terminate withinanupperch'arnber II. The diaphragm chamber is'supported upon the, valve casing I by a sleeve ordinverted cup I2 having a central boss I3 with a ribbed bore I l: axially therethroughwhich-guides thevalvestern 8 for vertical movement and affords free communicattion betweenthe inlet 'chamberofthe valve casing I and the lower section of the diaphragm chamber III. The valve stem 8 is secured to the diaphragm I5 and. terminates at its upper'end in a valve seat I6. When the. cut-off valve I is in normal open positions ball valve l'l rests upon the valve seat I6 ofthe valve stem 8 and thus breaks communication between the upper chamher I I and the inlet side of, the valve casing I.

The upper. chamber II is in free communication with theupper section of the. diaphragm chamber I0 through the sleeve I'I whichsupports the upper chamber; I I von the diaphragm chamber l0 andis of substantially larger internal diameter thanthe valveustem 8-. Thelowor-wall Id of the upper chamber slopesydownwardlyto a circular port: I9 from Which-a vent pipe :26 extends into the fire-box of the furnacefi. I Thecball valve ii is manually operable by a pull rod 2] which is slidable in a sleeve 22 mounted upon the top wall of the chambers l I, the. pullrodbeing connected to the ball valvecby a ilexibleiconnector 23. A removablecapl 2d islfitted over the upper end of the sleeve 22 to seal the chamber I I.

A trip-rod 25 extendsupwardly fromthe bot tomcwallofthe chamber II closely, adjacent the valve stemi to terminate below the normal upper position of thevalve seat It of the valve stem 8 butin-positionito engagethe ball valve I7 and displace {it froin'valveseat .I 6 when the valve stem 8; is-movedinto lowered position by a collapse of the diaphragm I5. Asolenoid 2Bis mounted on the; upper chamber II and has an armature 2i connecteditoazlever 28 which is pivotally mounted onthe chamber: II by a linkil; the linkage beingsuchthat a" preselectedcondition of eneris possible and is contemplated by the invention.'

A lifting pin 30 is preferably threaded into a bushing 3I set into the base of the valve casing I for lifting the valve I as a temporary expedient in the event of an electrical power failure or to obtain a limited flow of gas to re-light a pilot flame when the pilot is branched from the supply line or control apparatus beyond the automatic cut-off valve. The safety regulations in some calities prohibit the use of an emergency lifting pin or equivalent device, and the lifting pin will normally be omitted-from valves supplied to such localities. inadvertently supplied for installation where the lifting pin is banned, it can be sealed in inoperative position by pouring solder into the sleeve 32 which is integral with or secured to the bushing 3| and extends around the head of the'pin to preclude inadvertent adjustment thereof in localities where it is permitted.

- A pressure gauge 33 may be connected by a pipe 34 to a connector 35 which is tapped into the casting I2, and a second pressure gauge 36 may be mounted upon the chamber I I to indicate, by reference to the gauge 33, the condition of the cut-off valve. With normal inlet pressure registered at gauge 33, a reading of substantially zero at gauge 36, as in Fig.2, indicates that the cut-off I is open, since chamber I I is then vented through the port I9. With the same indication of normal inlet pressure at both gauges, as in Fig. 3, the service man knows that the cut-off valve I is closed but can be re-opened if the abnormal condition which caused the valve I to close is no longer present. If gauge 33 indicates zero pressure, or an abnormally low or abnormally high pressure, the service man knows that the cut-off valve can not be immediately reopened.

Electric current is supplied to the solenoid 26 through the temperature responsive switch 31 which consists of the housing 38 containing the stationary contact 39 and the movable contact 46 carried on the lever M which is pivotally mounted at 42 and connected at 43 to the fusible link 44. The spring it bears against the lever 4| and tends to separate the contact 39 and which normally are held together by the link 44. Upon exposure to abnormally high temperature the link 44 melts and permits the lever tI to be moved by the spring 45 to separate the contacts 39 and Ml. The link 14 must be replaced by a new one before operation of the cut-off valve can be restored.

The method of operation of the apparatus will now be described. Under normal operating conditions the several parts of the apparatus are as shown in Fig. 2, and the valve 7 is open as the inlet gas pressure is applied to the lower face of diaphragm I5 through the bore I4, and the pressure above the diaphragm is atmospheric or less due to the venting of the chamber I I through the port I9. If the gas pressure drops below some preselected value, the diaphragm I5 will drop by gravity and will move the valve stem 8 downwardly to close the valve I and to displace the ball valve I I from its seat I6 by engagement with the trip member 25. The ball valve I! will then roll down to seat on the vent port I9 and close the If avalvewith a lifting pin is' same. The cut-off valve may be closed by other abnormal conditions, for example by excessive gas pressure, by a heavy shock which displaces the ball valve from its seat or by failure of the electrical control system which shifts the lever 28 to force the ball valve from its seat.

The valve 1 can be reset to open position only be removing the cap 24 and lifting the pull rod 2| to reseat the ball valve I'I upon the valve seat I6 at the upper end of the valve stem 8, and this reseating is possible only when the abnormal conditions which caused the closure of valve I no longer exists. Assuming normal gas pressure at the inlet side of the valve casing I, as indicated in Fig, 3 by the pressure indications of gauges 33 and 36, the diaphragm I5 will rise when the ball valve I! is lifted from the vent port I9 of the chamber II, since the vent port is of relatively large diameter with respect to the inlet opening 9 of the hollow valve stem 8. The cut-off valve is thus opened by the lifting of the diaphragm I5, and the valve seat I3 of the valve stem 8 is ele vated into position to receive the ball valve I1. If all operating conditions are correct, the ball valve can be lowered into position upon the valve seat I6, thus blocking the flow of pressure gas into the chamber. I I, and the cut-off valve '1 will be held in open position by the gas pressure upon the lower face of the diaphragm I5. In case of a failure of the electrical power or of a defect in the electrical control circuits, as is indicated in Fig. 3, the lever 28 extends at least partially over the valve stem 8 and blocks the seating of the ball valve I'I upon its seat I 6. The fact that the defect is in the electrical system is immediately apparent since the pressure reading of gauge 36 will indicate a normal supply of gas.

While the invention has been described with reference to the supply of gas to a burner, it is to be understood that the safety cut-off valve may be employed with advantage in pressure gas lines supplying components to chemical reaction chambers. Some type of automatic alarm will usually be provided in such applications of the invention as the failure to introduce the pressure gas will result in defective operation and possibly will give rise to a dangerous condition.

The invention is not limited to the particular embodiment herein illustrated and described as various changes which may be made in the design and arrangement of the several parts fall within the spirit and scope of the invention as set forth in the following claims.

. I claim:

1. A safety cut-off valve for use in a pressure gas line comprising a valve casing divided into an inlet chamber and an outlet chamber by a partition provided with a valve seat, a valve element cooperating with said valve seat, a hollow valve stem carrying said valve element and having a port affording communication between its bore and the inlet chamber of the valve casing, a diaphragm chamber above said valve casing and an upper chamber above said diaphragm chamber, a flexible diaphragm extending across said diaphragm chamber and secured to said valve stem to actuate the same, the lower and the upper sections of said diaphragm chamber being in communication with the inlet chamber of the valve casing and the upper chamber respectively, said hollow valve stem extending upwardly to terminate in a valve seat within said upper chamber, a vent port in the bottom wall of said upper chamber and of greater gas-carrying capacity than said hollow valve stem, a ball valve adapted to seat upon the valve seat at the upper end of said valve stem or alternatively upon said vent port, thereby to vent pressure gas from the upper chamber and the upper section of the diaphragm casing or alternatively to equalize the gas pressures in the sections of the diaphragm casing, and a manually operable flexible connection to said ball valve for lifting the same from said vent port and into position above said valve stem seat, said ball valve being displaceable by abnormal shock from its seat on the hollow valve stem.

2. A safety cut-01f valve as recited in claim 1, in combination with stationary trip means in said upper chamber for displacing said ball valve from its seat upon a preselected lowering of said valve stem due to reduced pressure within said inlet chamber of the valve casing.

3. A safety cut-off valve as recited in claim 1, in combination with electromagnetic means for displacing said ball valve from its seat on said hollow valve stem upon a preselected condition of energization thereof.

4. A safety cut-ofi valve as recited in claim 1, in combination with a pressure gauge secured to the upper chamber to indicate the gas pressure therein.

5. A safety cut-off valve as recited in claim 1, in combination with a lifting pin threaded into the valve casing and manually adjustable to lift the valve element from its seat against the clos ing force exerted upon said hollow valve stem by said diaphragm.

6. A safety cut-off valve as recited in claim 1, in combination with electromagnetic means for displacing said ball valve from its seat on said hollow valve stem upon failure of the supply of electric current to said electromagnetic means and means in the electric circuit responsive to abnormally high temperature for breaking said circuit.

TIMOTHY J. SULLIVAN.

References Cited in the file of this patent UNITED STATES PATENTS 

